In many of today's businesses, notification to and approval by a hierarchy of people must often be made during the course of a project. For instance, a purchase order request from a project engineer may have to be approved through a pertinent chain of command which includes the head of the Engineering Department, the Purchasing Department and the Accounting Department. This approval process is usually accomplished by an inter-office document on which the various people in the chain of command respond.
With the advent of the computer, similar communication is enabled by electronic mail. Notification to and approval by the various pertinent people is accomplished by an originator (sender) sending a copy of a document or message to the necessary people via electronic mail. The message may be duplicated and distributed simultaneously to multiple receivers, or the message may be serially circulated from one desired receiver to the next. Typically, the electronic mail system also enables a reply response to be sent back to the sender from each receiver.
Various developments in electronic mail systems have been made in the past few years. Most improvements address efficiency and speed of electronic mail systems, and automating certain features such as return receipts and notices to a sender from a receiver indicating that he will not be answering any mail until he returns from vacation.
Other developments have been made in the distribution/circulation capabilities of electronic mail systems. In a typical circulation scheme of a message, a sender specifies on a list, which is part of the message, the desired recipients of the message. The list is usually arranged in order of to whom the message is to be sent first, second, and so on. The message is serially sent (i.e. sent to one person at a time) to each of the listed recipients. One circulation scheme enables a recipient to add his comments to the message before sending the message to the next recipient. Another circulation system attempts to control the number of copies made of a sent message in a distributed control environment. Other circulation systems enable the circulation of different media including text, graphics and images.